Air cleaner



AIR CLEANER Filed Deo. 28, 1956 FIEZ.

JAMES H. MA F1 y BY N5 ELD ATTYS,

c ,A V2,825,318 :PatentedMar. 4,1958

' 2,325,318 AIR ,CLEANER (JamesH.iMansfield, Philadelphia, Pa.

Application DecemberzZS, 1956, Serial No. 631,261

3 Claims. '(Cl. 1215-4156) This invention relates-,to apparatusforsupplying clean air to the carburetor of aninternal combustionengine, or to otherdevice or mechanism rwhich requires a ysupply ofsubstantially dust-free air.

It is well known that dust or othersolid matter of any kind carried byincoming air into a carburetor or engine combustion chamber tendsto-clog the jets and valves of the carburetor and chamber and thereby torender the engine inoperative until the rsolidrnatter is removed fromall small oriiices and openings through which the air must pass incontrolled quantities. Furthermore, internal enginefparts are subjectedto `excessive wear if dirt or dust is permitted to flow into Athecombustion chamber. Two cycle engines are especially vulnerable toforeign particles, due to the type of intake-valves used, which areeither reed or rotary. f The necessity of providing air-cleaning meansis accordinglyrrecognized.

One ofthe `nowconventional methods of cleaning air on its way toyacarburetoristopass it through a filter, of which there are-varioustypes. Such filters are, in general, elhcient andsatisfactory, but haveone drawback, viz.: they accumulate ine-themselves the solid matterfiltered out of the air as itpassesthroughthem, with'the eventual resultof reducing the amount kof rair that can pass through the iilterinconsequence of which Vthe ,carburetor receives graduallyless and lessairuntil it isvunable to deliver the requisite volume of fuel-'laden airVto the engine or to maintain the proper-mixture of air and fuelnecessary to good engine performance. Accordingly, Yit is necessary toclean the lter more or less frequently. Moreover, lilters may get wetand freeze solid during cold weather use.

This invention obviatesthe need of an air filter and deliverssubstantially dust-free air, at the'same time automatically disposing ofthe solid matter removed from the air.

This invention also delivers air to the carburetor at constant andslightly more than atmospheric pressure, which contributes to theeliiciency of the carburetor.

This invention is Yapplicable to any air cooled internal combustionengine or other mechanism which comprises an enclosed fan whichfunctions so as to produce a centrifugal flow of air the course of whichmay subsequently be changed and so channelled and directed as to beuseful.

It is conventional to provide such a fan with a screen over its intakeopening. Sometimes more than one screen is incorporated, and in someinstances a screen is so mounted as to rotate with the fan. Suchscreens, however, must be relatively coarse and open, so that theyfunction only to exclude large particles such as chips, pebbles, grass,leaves, straw, feathers, strings or other such bodies which may bepresent in the air in the vicinity of the fan and associated mechanism.The screen does not lter the air to the extent of excluding smallparticles, for the exclusion of small particles is not necessary to thecontinuous and satisfactory functioning of the fan.

In the accompanying drawings:

Fig. 1 is a top view of a'small internal combustion engine made inaccordance with the invention;

Fig. 2 is an end elevational view of theengine from the 'the powertakeoff side;

Fig. 3 is a side viewv of the engine with a portion of the fan shroud orhousing broken open so as to render the fan visible;

Fig. 4 is a view in perspective of the fan detached fromA the engine;

Fig. 5 is a fragmentary'side elevation and partial sectional view ofanengine with a different type of fanwithin the scope of the invention,and

Fig. 6 is a sectional view on the line 6,6, Fig.5.

Withr reference 'to the drawings, the invention comprises a rotary fan 1of centrifugal type which in operation tends to impel air radially intoa shroud 2. The shroud Z encloses the fan and has a screened opening 3adapted to admit outside air axially to oneV side of the fan adjacentthe axis 4 of the latter, said shroud also having another opening 5adjacent the periphery and'in the present instance at the top of the fanadaptedto discharge the air in-a desired direction. A radial baie 6forms a solid wall in proximity to the side of the fan-remote from theadmission opening 3; and a tube 7, constituting the air supply duct of acarburetor 8, has its intake end in proximity to the said bafe asillustrated. The bafe may be stationary or may be integral with orotherwise rotatable with the fan. The inner or'rear wall 9 of the shroudextends upwardlyin spaced relation to and at the back of the baile 6 toa point near the outer peripheryof the fan and in the present instancethe upper edge 10 of thewall defines the lower edge of the dischargeopening 5.

A suitable assembly in accordance with the principle rof the invention,therefore, consists of a fan having a radial Wall on the side of itsfins or blades which lies remote from the intake opening of a'shroud, sothat only air newly admitted through said opening reaches the axial areaof the fan, said baffle providing a space adjacent the shaft of the fanon the side remote from the said intake opening, which space isaccessible during operation only to air which has been subjected to theaction of the ns .or blades of the fan.

It is not necessary that the solid wall which functions as a baffleextend to the periphery of the fan. lts essential location and extent isadjacent the axis of the fan.

l A particular advantage from the standpoint of economy andpracticability arises from the fact that the fan and other componentassemblies and parts comprised inthis invention are to be found in manyair cooled internal combustion engines in substantially the requiredform, while in practically all others a fan Yconforming to thefunctional requirements of this invention can be substituted and abaffle provided separately if not made integral with the fan, and suchprovisions will perform all of the functions required therefrom forother purposes, the prime purpose of a fan `in operative combinationwith an air cooled internal combustion engine being to circulate air toand around the engine cylinder or cylinders.

A typical air cooled engine assembly is illustrated in Figs. 1 to 4 ofthe drawings wherein, in'addition to the elements previously described,the crankcas'eof the engine is shown at 12, the fan 1 being mounted onone end of the shaft 13 of the engine. The engine cylinder or cylinders14 occupy an upright position in the discharge opening 5 of the shroud2, said opening terminating in the present instance in louvers 15 whichshield the cylinder.

at a filter) to convey cleaned air to the carburetor, said opening beingso disposed as to allow the movement into said tube of air from whichdust and other solid matter hasbeen removed by the operation of the fan.

In imparting velocity to air the fan incidentally imparts velocity tothe dust or otherv solid particles present in the air. The fan with itsshrouding is adapted to deliverl a major portion of the air passingthrough it to a selected locality, radially and/ or tangentially, beyondthe periphery of the fan where cooling effect is desired, and dust andother small particles of solid matter are carried along with such majorportion ofthe air, without detriment to the cooling function since thereis ample space for its passage.

Such minor portion of the air as does notjoin the main current andpromptly escape, deviates from the direction in which the dust and otherparticles are impelled by the direct action of ,the fan or by theresulting (partially deflected) current. Inertia of motion causes thedust and other solid particles to `continue to travel in the directionin which they are impelled by the fan or by the air current travellingat the highest speed with the least change of direction` Accordingly,the dust and other solid particles do not travel with the slower movingair that eddies back into space near the fan shaft, remote from the mainoutlet and on the side of the bathe remote from the influx of outsideair, where an air opening is provided for its exit into a tube leadingto the carburetor.

In an experimental operative embodiment of this invention, a trap with aremovable cap at the bottom was provided in the tube leading from suchan opening to the carburetor, but even after running the engine for aprotracted period of time no deposit of dust particles or other foreignmatter was found in the trap. Meantime, throughi out extensive andlengthy service tests the engine maintained peak performance and noadjustment or servicing was necessary as a result of dust or foreignmatter entering the carburetor.

Incidental to directing the flow of air from the fan to the locationdesired, and for the purpose of so doing, a fan such as described isnecessarily associated with a surrounding shroud which confines the airexcept Where its egress is desired. Such a surrounding shroud functionsto restrain the escape in undesired directions of air driven by the moition of the fan, and by confining said air to predetermined course offlow, and `in so doing brings about the accumulation within itself ofair pressure slightly in excess of and more uniform than the atmosphericpressure outside of the shroud. This increased and uniform pressure iseffective at the opening provided for the escape of air which passestherefrom to the carburetor, and results in improved functioning of thecarburetor.

I claim:

1. In combination with an air cooled internal combustion enginecomprising `a carburetor, a centrifugal fan having air-impelling blades,bathe means at one axial side ot' the fan restricting the axial ow ofair to the blades to one side only of the fan, shroud structureenclosing said fan and baffle and having an opening for admission of airaxially to the said one side of said fan, and having also an opening forthe discharge of air from the periphery of said fan, and an opening insaid shroud structure adjacent the axis of said fan and on the side ofsaid baffle remote from said blades for the delivery of air to thecarburetor.

2. In combination, a centrifugal fan having an axis, shroud meanssubstantially enclosing said fan and having an inlet port for admissionof air axiallyto one rside only of said fan, said shroud means alsohaving a discharge portiradially remote from said axis, a radial baffleat the other side of said fan, and air-withdrawal port means having anentrance near said axis between said baffle and said shroud for thewithdrawal, `for external use, of air which has passed radially throughsaid fan and around said baffle into space near said axis between saidbaffle and the side of said shroud opposite said inlet port.

3. Apparatus for providing a supply of air from which any suspendedsolid matter has been removed by centrifugal impulsion, said apparatuscomprising a centrifugal fan having air impelling blades and an axis, ashroud substantially enclosing said fan, an inlet opening in said shroudadjacent said axis for admission of air axially to one side only of saidfan, a discharge port in said shroud radially remote from said axis forthe discharge of centrifugally impelled air and solid matter suspendedtherein, a bale located within said shroud on the other side of said fanbetween said fan and a side of said shroud opposite said inlet opening,the saidbafile extending radially from said axis and having an edgeremote from said axis, said bafde and said side of said shroud definingbetween them a space adjacent said axis into which air can enter onlyafter first passing beyond the said edge of said baille, and port meansfor withdrawing, for use outside of the apparatus, air which has passedaround the edge of said baffle into said space.

References Cited inthe file of this patent UNITED STATES PATENTS1,922,200 Frank Aug. l5, 1933

